A sense and destroy armor (SADARM) munition includes, inter alia a carrier projectile (not shown), at least one submunition 15, as shown in FIG. 1, having a first stage decelerator, also known as a ballute 16 (FIGS. 3 and 4), which is tucked into the aft end or storage module 18 (FIG. 3) of submunition 15, a deployment cord 20 (FIGS. 2, 3, 5 and 6) having a first end 21 detachably connected to ballute 16 and a second end thereof integrally fixed to an aft cover 22 (FIGS. 1-3), for instance, by a screw (not shown). Aft cover 22 is held to submunition 15 by a plurality of clips 24 (FIGS. 2 and 9) which are, in turn, held in place by a band 40 (FIG. 2). The submunition also includes a micro-processor, other timing devices, explosives, a fuze, and radar and infra-red sensors (not shown) for locating, locking onto and destroying targets.
In operation, the submunition is ejected from the carrier projectile and after a time delay band 40 on the submunition, holding clips 24 in position, is blown off by a small charge. The charge in combination with centrifugal forces is sufficient to dislodge clips 24 releasing aft cover 22 from aft end 18 of submunition 15. Centrifugal forces, in combination with the pull of deployment cord 20, pull ballute 16 from its storage cavity. Aerodynamic forces move the aft cover away from the deploying ballute and the first end 21 of the deployment cord ruptures so that the aft cover 22 falls independently of the submunition 15. The function of the ballute 16 is to reduce the spin rate and forward velocity of the SADARM submunition after it is ejected from the carrier projectile.
During test firings and post-inspection of such submunitions, technicians have found the ballute to be damaged. It is speculated that damage to the ballute results from contact between the aft cover and the ballute during ballute deployment. Damage to the ballute results in mission failure and the loss of a $5,000.00 submunition.
In order to solve this problem, three changes have been made. First, all of the exposed edges and cut-outs of the aft cover have been smoothed. In making this change it was believed that if ballute/aft cover contact occurred, the contact would be less damaging. Unfortunately, for some unexplained reason, such changes resulted in a greater rate of failure. In a second change, the rupture cord attachment screw was moved from an outboard location on the aft cover to the inside center of the cover; and third, different ballute packing techniques were tried. However, the loss of munitions still occurs at a remarkable rate because of damage to the ballute.
Accordingly, it is an object of the present invention to prevent loss of a submunition because of damage to the ballute on deployment.
Another object of the invention is to delay deployment of the ballute until after the aft cover is a safe and uncontactable distance from the ballute.
Other objects will become apparent by reference to the drawings and from the detailed description of the invention.